Stratum Spinosum(thickest layer)
–1AProduce more and more keratin filaments which causes cell to flatten; the higher up in this stratum, the flatter the cells appear
--2AThickest stratum in most skin–In thick skin, exceeded by stratum corneum
–3AConsists of several layers of keratinocytes
--3BKeratinocytes are firmly attached to each other by numerous desmosomes which partly account for epidermis’s toughness.
Histological fixatives shrink the keratinocytes causing them to pull away from each other, but they remain attached by desmosomes.
Desmosomes create bridges from cell to cell, giving, each cell a spiny appearance.
Epidermal Keratinocytes are also bound together by “tight junctions”, thus, essential for water retention
--4ADendritic cells found throughout this stratum
Numerous desmosomes and cell shrinkage produces spiny appearance
--5ANamed for artificial appearance (artifact) created in histological section
--6ADeepest cells remain capable of mitosis.
Cease dividing as they are pushed upward